Monster Rush! Lite is an online mobile game, action castle defense game, defend your castle with the touch of your fingertip, lead armies of soldiers, knights, archers, and wizards to save your world from raging evil monsters, is free (this version) on Android devices, from Prido Games.
Download the game at:
https://play.google.com/store/apps/details?id=com.Sagadio.MonsterRushLite&hl=en